Giacomo Miceli

Going like a bat

During the Pascal-B nuclear test, a 900-kilogram (2,000 lb) steel plate cap (a piece of armor plate) was blasted off the top of a test shaft at a speed of more than 66 km/s (41 mi/s; 240,000 km/h; 150,000 mph). Before the test, experimental designer Dr. Brownlee had estimated that the nuclear explosion, combined with the specific design of the shaft, would accelerate the plate to approximately six times Earth’s escape velocity. The plate was never found, but Dr. Brownlee believes that the plate did not leave the atmosphere, as it may even have been vaporized by compression heating of the atmosphere due to its high speed. The calculated velocity was sufficiently interesting that the crew trained a high-speed camera on the plate, which unfortunately only appeared in one frame, but this nevertheless gave a very high lower bound for its speed. After the event, Dr. Robert R. Brownlee described the best estimate of the cover’s speed from the photographic evidence as “going like a bat!”

The myth of the “manhole in space” has since been discredited, so it’s unlikely you will bump into it orbiting around the sun.